belcher in a murder-suicide over the weekend. and the titans receiver shot himself and jr. seau, and atlantic falcon safety, as well, and his occupy showed he had a britain disease linked to repeated concussions. last year the former bears star shot himself in the chest. he left a note saying, please, see that my brain is given to the nfl. he had brain damage related to his hard hits. now this new study, new study that just came out, adding to the body of evidence linking repeated brain injuries or head injuries to brain damage. and republickers have found that 80 percent of people with a history of mild brain trauma later showed signs of damage that can cause depression and dementia. our doctor joins us, a specialist in head and brain injuries. thank you, doctor. a lot of these injuries, and it feels like we are in news from the future on the >>guest: it does. today's story about the boston university report is significant because as you said, more than 68 of the 89 people they studied had some evidence of getting hit frequently. they played professional experts, 55 of the